Four people have been jailed for a total of 31 years for their roles in an international plot to smuggle cocaine worth £164million into the UK.

Dawne Powell, 56, James Hill, 31, David Webster, 44, and Philip McElhone, 30, were sentenced at Leeds Crown Court after a tonne of the class A drug was seized from a yacht off the coast of Ireland in September last year. They are the final members of a gang to be jailed for 73 years in total for their parts in the operation.

The yacht Makayabella after it was seized. Picture by Brian Lawless/ PA Wire.

The Makayabella yacht was seized by the Irish Navy on September 23. It had transported the drugs from Venezuela and was to transfer its cargo to another vessel, the Sea Breeze, skippered by Dawne Powell’s husband Stephen and crewed by McElhone and Webster, out at sea but the second boat ran out of fuel on the way to the meeting point. The Sea Breeze was rescued by the RNLI and the Makayabella was seized.

Authorities discovered 1,025 blocks of high-purity cocaine weighing 1kg each on board. Its street value was around £164m.

At yesterday’s hearing, Hill, from Ilkley, West Yorkshire, was found guilty of conspiracy to import cocaine and jailed for six years, Powell, from Guiseley, West Yorkshire, was convicted of money laundering but cleared of a charge of conspiracy to import cocaine before being sentenced to three years in jail.

Webster, from Otley, West Yorkshire, and McElhone, from Halton Moor, Leeds, pleaded guilty to conspiracy to import cocaine at an earlier hearing and were jailed for 11 years each.

Sentencing Hill, Judge James Spencer QC said: “This was a serious conspiracy. It involved a colossal amount of cash, or the prospect of it, because the street value of the quantity of cocaine which was planned to be imported was over £160m. And the quantities of illegal profit therefore were mind-boggling.”

Powell bought and insured the Makayabella, bought flights to the Caribbean for her husband Stephen and his father John Powell to collect the boat, bought equipment for the yacht and paid for the Sea Breeze vessel.

She told the court she did not know her husband was involved in the plot and thought he wanted the Makayabella to sell on.

Judge Spencer told Powell: “I’m quite satisfied that you knew what (Stephen Powell) was about, I’m quite satisfied you knew what was involved. Notwithstanding that knowledge, or your suspicion of it, you made that money available.”

Her husband was jailed for 16 years in December for orchestrating the operation, while her father-in-law, 70, from Silsden, was jailed for 10 years after admitting drug trafficking and importation earlier this year.

Benjamin Mellor, 35, from Bradford, and Thomas Britteon, 28, from Grimsby, North East Lincolnshire, were also jailed for eight years each for their involvement.

David Norris, National Crime Agency branch commander, said: “We have successfully dismantled an organised crime group intent on flooding the north of England with illegal drugs.

“This was a colossal seizure, and I’ve no doubt that, had it not been stopped, the cocaine on board the Makayabella would have ended up on our streets.”